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FLORIDA GEOLOGICAL SURVEY-I5TH ANNUAL REPORT 
pillar slightly twisted; outer lip, within, with seven denticulated ridges, 
the posterior one being the largest; inner lip with callus upon which an 
irregular ridge extends parallel with and close to the outer margin. 
Type (U. S. N. M. Cat. No. 352278). This measures: length 10.2 
mm.; greatest diameter 4.2 mm. 
Type locality: Well (depth 65—100 ft.) at Kissimmee, Osceola 
Co., Fla., G. C. Matson, collector, 1908. U. S. Geol. Surv. Sta. No. 5016. 
Geologic horizon: Probably Miocene. 
Discussion: This species is closely related to the northern Miocene 
form, Astyris communis (Conrad) ; but in the former, the suture is 
only slightly appressed, the spiral bands on the base more numerous, 
extending farther up the basal slope. In addition, “A. communis, in 
some specimens, shows distinct traces of narrow color-bands extending 
across the whorls in a direction nearly parallel with the axis of the shell 
and slightly flexuous.” (See Dali, Wagner Free Inst. Sci., Vol. Ill, pt. 
1, p. 138.) 
When the new species is compared with Astyris profundi Dali, 
the suture of the latter is found to be more appressed, the whorls more 
inflated, and the basal sculpture finer and more narrowly anteriorly 
confined. 
This new species is named in honor of the collector, Mr. George 
C. Matson. 
CAECUM PUTNAMENSIS N. SP. 
Plate I, Figures 1 and 2. 
Shell small, thin, arched, and slightly tapering; surface almost 
smooth but under magnification shows faint, irregular annulations. and 
growth lines; posterior end of tube very near the margin, slightly im¬ 
pressed, forming a narrow, low, and inconspicuous ring; plug smooth, 
hemispherical and extending a little beyond the margin of the tube; 
mucro small, short, rounded and situated near the margin and a little 
to the right of the median plane of the shell; anterior end of tube swollen, 
forming a narrow ring near the margin; anterior margin entire. 
